Standardized test scores do no predict adult income. But something else does...

A paper produced at Stanford in 2008 found that students' behavior in middle school predicted adult income better than test scores. In fact, middle school test scores only predicted income for men with postsecondary degrees. The interesting part is how the researcher measured behavior: she simply asked two teachers to answer the following five questions.

"Is [the student] frequently absent? Is [the student] frequently tardy? Is [the student] consistently inattentive in class? Is [the student] frequently disruptive? Does [the student] rarely complete his homework?"

Makes sense to me. 

Here is a link to the study